Drier



May s, 192s.

O. NORDSTRM DRIER Filed Nov. 5, 1925 2 Sheets- Sheet 1 INVENTOR BY JWM/wf if@ ATTORNEY My s, 192s. 1,669,012

O. NORDSTRM DRIER Filed Nov. 5, 1926 2 Sheets-Sheet 2 :immuun /J ATTORNEY l 50 for'carrymg away gases.

Patented 'May 8, 1928. v

UNITED STATES PATENT OFFICE.

OTTO N ORDSTRM, 01? SUNDSVALL, SWEDEN.

DRIRE.

Application led November 5, 1926, Serial No. 146,556, and in Canada December d, 1925.

invention relates to drying plants for drying such substances as wood c ips. More particularly the invention relates to thattype of dr ing plant or drying tower in e which divi ed material. to be dried descends through the tower in a substantially vertical direction while hot gas or hot air passes through the descending material in a substantially horizontal direction` i'or the purpose of drying the material.

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Between inner cylindrical wall 1 and anr outer cylindrical wall 2, which `is also Yper-y foi-ated, is an .annular space 17 serving as A a passageway for wood chips or other materia'l to be dried. At the-top 'of the inner cylindrical wall lisa cone member 1 8 which directs the 'material intol space 17;" f' Material is received atvtheffupper 'partei the drierv from a belt'1'.eonveyefr 3A or. other"v ieeding;

I the lower'end of Vouter cylindrical-'wall 2 and.'spacedv therefrom 'is a rotary bottom 4 which .serves as a dischargemember for `the dried material.,v 4The dried material passes between the lower end of cylindrical 4o wall `.faiid'the rotating bottom and is discharged through an opening 19 onto-a 'niember'20 for carrying` away theffinished vproduct, which member: may-consistof a elt conve er', 'as` indicated. The bottom 4f 4 5 isfmounte Ingen-rollers .21,andiisfgiifided'by may be drivenfbyfa'n'y desired mechanical means. jcyli'ndrical brick wall ''forms thek outer 'casing of the tower proper. In theupperpart of the casing is a stack 7 The lower part of the wall 5 is brought intov the outer wall 2 as indicated at 23. Between wall 5 and outer cylindrical perforated wall 2 is an annular space 24. The brick wall 5 is not perforated. i g t Hot drying gases aresupphed to the central chamber 25 which is the space within inner cylindrical perforated wall 1 and these gases pass through the perfor-ations in wall 1, thence through the material to be dried within space 17, thence through the perforations in wall 2, thence linto space 2d and part of the gases then pass into stach 7 and part are diverted by means of a partition 111 to be recirculated back into central chamber 25.

Het gases are supplied through conduity l0. ri`hese gases may2 for example, be the waste gases from a boiler or a soda furnace. A blower 9 which may be of any suitable type driven mechanically from any desired type of motor, draws gas from conduit 10 and 'forces Iit into passageway 8 which connects with central chamber 25 to'supply the gases thereto. Branched into conduit 10 is a recirculating passageway 11 which is connected with casing 5 at substantially the central portion of the outer cylindrical wall 2. Within recirculating conduit 11 is a damper 12 which may be o erated to vary the flow or' gas through con uit 11. Damper 12 may be operated and preferably is operated by meansof 'a thermostatic member 13 respon- Vsive to changes of temperature in the gases supplied to central chamber 25. This thermostatic element may be, as shown, mounted in ,Y passageway 8.v Reference character 27 designates a servomotor for operating damper vl2 and reference character 28 deslignates` apilot valve' vfor operating servomotortr27. Regulators for operating damp- -ers are known. and-any of various ktypes may be used for my drying plant? The most important feature of my inventionA is the member 14 which might be termed a partition, a baille, or a shelf. This artition is inserted between the outer perorated wall 2 and the surrounding brick wall 5 at about the middle portion of the tower. VThe baiile extends in a substantially horizontal direction and is arranged so that its outer circumference lies within the opening of recirculating conduit 11. The artition 14 operates to direct the gasesw ich pass through that portion of the material which is below the partition into the recirculating conduit since this portion of the gas passes back through blower 9 to be recirculated through the material to dried. As the material passes downwardly through space 17, it becomes drier as it pro sses until the material at the lower endo space 17 is quite dry. Consequently the gases passing through the lower portion of space 17 do not have so much moisture to take up as the gases passing through the upper portion of the material to be dried. The drying possibilities of the lower strata of gas are therefore not fully utilized and I recirculate this ortion in order to obtain 11nproved resu ts. Partition 14 is situated so that, when damper 12 is open an appreciable extent, a portion of the gas passing through the tower at a higher level than that of the partition is also returned to the blower and to chamber 25. Furthermore, if damper 12 is entirely or substantially closed, gases passing through the portion of the material which is below aliie 14 pass around the edge of baille 14 and upwardly to stack 7. For any particular tower, the 4partition 14 may be adjusted at that position which gives the 'best results. The gas which is not recirculated passes upwardly through space 24 and through stack 7 to be dispersed into the atmosphere. By means of the apparatus above described only fully saturated and fully utilized gas escapes to the stack.

In the embodiment shown in Fig. 2,'the partition 1li is arranged upon a series of lexible members such as wires 15 which pass over pulleys 30 and are connected to counterweights 16 for the purpose of altering the height of partit-ion 14. It desired, the adjustment of partition 14 may be automatically controlled in accordance with the temperature of exhaust gases.

vWhile I have described my invention as applied to one or more forms of apparatus, it is to be understood that the invention is not limited to the embodiments herein disclosed and described.

What I claim is:

1. In a drying plant, in combination, members forming a vertically extending annular compartment for the reception of material to be dried and surrounding a central chamber, a casing wall surrounding said members forming a space surrounding said compartment, a conduit for supplying gas to said central chamber, a stack connected to the upper portion of said casing, a recirculating conduit connecting the lower portion of said casing with the conduit for supplying gas to the central chamber and a horizontal alile shelf between said annular compartment and the casing arranged above a portion of the recirculating conduit.

2. In a drying plant, in combination, members forming a space for the reception of material to be dried, means to supply drying fluid to said space, an outlet for carrying away fluid from said space, a conduit for reeirculating iluid from said space and back to said space, a damper in said conduit, automatic means for controlling said damper and bailing means for directing the relative amounts of fluid passing` into said outlet and said conduit.

3. In a drying plant, in combination, vertical members forming a space for the reception of material to be dried, means to supply drying uid to said space, an outlet for carrying away fluid from said space, a lconduit for recirculating fluid from said space and back to said space, a damper in said conduit, automatic means responsive to variations ot temperature in the fluid supplied to said space for controlling said damper and battling means for directing the relative amounts of fluid passing into said outlet and said conduit.

4. In a dryin plant, in combination, a vertically exten ing annular compartment for the recept-ion o material to be dried, a casing Wall surrounding said members and formmg a space surrounding said compartment, a supply conduit connected with the center of sai compartment, a stack connected to the upper portion of said casing, a recirculating conduit connecting the lower portion of said casing with said supply conduit, a balile within the space surrounding said compartment arranged to define paths of flow through said compartment and means for controlling flow through said recirculating conduit.

5. A drying plant comprising an inner wall adapted for passage of gas therethrough, an` outer wall adapted for passage of gas therethrough, said walls forming between them a vertically disposed annular space for the reception of material to be dried through which gas is adapted to pass, a gas supply conduit connected to the space within the inner wall for supplying gas thereto, means forming a vertically extending outer annular space outside the outer wall, a stack for removing gas from the up-` per part of the outer annular space, a recirculating conduit arranged to receive gas from the outer annular space and connected to the gas supply conduit, a baille shelf situated within the outer annular space and arranged opposite the connection of the recirculating conduit with the outer annular space and a damper in the recirculating conduit for controlling flow of gas therethrou h. l

6. l drying plant comprising an inner wall adapted for passage of gas therethrough and lforming a central chamber, an outer wall adapt-ed for passage of gas therethrough, said walls forming between them a vertically disposed annular space for the reception of material to be dried through which gas is adapted to be passed, a gas supply conduit connected to the bottom of the central chamber for supplying gas thereto, a wall forming a vertically extending outer annular space around the said outer wall, a

midway of the outer annular space and separating the outer annular space lnto two parts, one above the other, a stack for removmg gas from the upper part ot' the outer annular compartment, a recirculating conduit connected to remove gas from the lower part of the outer annular space and connected to supply gasto the gas supply conduit and a damper in the recirculating conduit for controlling flow of gas therethrough.

7. A drying plant comprising an inner wall adapted for passage of gas therethrough and forming a central chamber, an outer wall adapted for passage of gas therethrough, said walls forming between them a vertically disposed annular space for the reception ot material to be dried through which gas is adapted to be passed, a gas supply conduit connected to the bottom of the central chamber for supplying gas thereto, a wall forming a vertically extending outer annular space around the said outer wall, al horizontal baille shelf arranged sub stantially midway of the outer annular space and separating the outer annular space into two parts, one above the other, a stack for ,removing gas from the upper part of the outer annularcompartment, a recirculating conduit connected to remove gas from the lower part of the outer annular space and connected to return gas to the central chamber and a damper in the recirculating con# through, said walls formlng between them a "ertically disposed annular space for the reception of material to be dried through which gas is adapted to be passed, a gas supply conduit' connected to the bottom of the central chamber for supplying gas thereto, a wall forming a vertically extending outer annular spa-ce around the said outer wall, a horizontal baille shelf arranged substantially midway of the outer annular space and separating the outer annular space into two parts, one above the other, a stack for removing gas from the upper part of the outer annular compartment, a .recirculating conduit connected to remove gas from the lower part of the outer annular space and connected to supply gasto the gas supply conduit, and means responsive to variations of temperature in the gas supplied to the central chamber for controlling said temperature. A

ln testimony whereof I hereunto atlix my signature.

orro NoRDsTRoM. 

